Chapter 18, Problem 28P

Interpretation Introduction

Interpretation:

The product of the reaction of cyclopentanone with the given reagents is to be predicted.

Concept Introduction:

Lithium aluminum hydride and sodium borohydride are strong reducing agents. They are inorganic compounds which are used as the reducing agents in organic synthesis. They used for the conversion of aldehydes and ketones into primary and secondary alcohols.

In the reaction of alkenes, alkynes and other functional groups, catalytic reduction is commonly used. The catalytic reduction of carbonyl groups is less by this method because of the modern use of complex hydride reagents.

By catalytic hydrogenation, aldehydes are reduced to primary alcohols. Grignard reagents react with ketones and aldehydes to form alcohols. These reactions are nucleophilic addition reactions. The Grignard reagent adds to the carbonyl group of aldehydes and ketones due to electronegativity difference between carbon and oxygen.

An organolithium reagent acts like a good nucleophiles and strong bases. They used for the conversion of aldehydes and ketones into primary and secondary alcohols. Acetal is an organic compound with general formula $\text{RHC}{\left(\text{OR'}\right)}_2$.

Answer to Problem 28P

Solution:

a) The product of the reaction of cyclopentanone with lithium aluminum hydride, followed by water is shown below.

b) The product of the reaction of cyclopentanone with sodium borohydride, methanol is shown below.

c) The product of the reaction of cyclopentanone with hydrogen (nickel catalyst) is shown below.

d) The product of the reaction of cyclopentanone with methylmagnesium iodide, followed by dilute acid is shown below.

e) The product of the reaction of cyclopentanone with sodium acetylide, followed by dilute acid is shown below.

f) The product of the reaction of cyclopentanone with phenyllithium, followed by dilute acid is shown below.

g) The product of the reaction of cyclopentanone with methanol containing dissolved hydrogen chloride is shown below.

h) The product of the reaction of cyclopentanone with ethylene glycol, p-toluenesulfonic acid, benzene is shown below.

i) The product of the reaction of cyclopentanone with aniline $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{NH}}_{\text{2}}\right)$ is shown below.

j) The product of the reaction of cyclopentanone with dimethylamine, p-toluenesulfonic acid, benzene is shown below.

k) The product of the reaction of cyclopentanone with hydroxylamine is shown below.

l) The product of the reaction of cyclopentanone with hydrazine is shown below.

m) The product of the reaction of cyclopentanone with product of part (l) heated in triethylene glycol with sodium hydroxide is shown below.

n) The product of the reaction of cyclopentanone with p-Nitrophenylhydrazine is shown below.

o) The product of the reaction of cyclopentanone with semicarbazide is shown below.

p) The product of the reaction of cyclopentanone with ethylidenetriphenylphosphorane is shown below.

q) The product of the reaction of cyclopentanone with sodium cyanide with addition of sulfuric acid is shown below.

r) The product of the reaction of cyclopentanone with chromic acid is shown below.

Explanation of Solution

a) The product obtained by the reaction between cyclopentanone and lithium aluminum hydride followed by water.

The reaction of cyclopentanone with lithium aluminum hydride, followed by water gives alcohol as the final product. Lithium aluminum hydride reduces cyclopentanone to cyclopentanol. The product of this reaction is shown below.

b) The product obtained by the reaction between, cyclopentanone and the reagent, sodium borohydride, methanol.

The reaction ofcyclopentanone with sodium borohydride, followed by methanol gives alcohol as the final product. The product of this reaction is shown below.

c) The product obtained by the reaction between cyclopentanone and the reagent, hydrogen (nickel catalyst).

The reaction of cyclopentanone with hydrogen in the presence of nickel catalyst gives cyclopentanol as the final product. The product of this reaction is shown below.

d) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, methylmagnesium iodide, followed by dilute acid.

The reaction of cyclopentanone with methylmagnesium iodide that is Grignard reagent, followed by dilute acid gives alcohol as the final product. The product of this reaction is shown below.

e) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, sodium acetylide, followed by dilute acid.

The reaction ofcyclopentanone with sodium acetylide, followed by dilute acid gives alcohol. The product of this reaction is shown below.

f) The product obtained by the reaction between, cyclopentanone and the reagent, phenyllithium, followed by dilute acid.

The reaction of cyclopentanone with phenyllithium, followed by dilute acid gives alcohol as the final product. The product of this reaction is shown below.

g) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, methanol containing dissolved hydrogen chloride.

The reaction of aldehydes and ketones with two equivalents of an alcohol results in the formation of acetals. The product of this reaction is shown below.

h) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, Ethylene glycol, p-toluenesulfonic acid, benzene.

In the reaction of ketone with ethylene glycol, p-toluenesulfonic acid and benzene, the protection of the carbonyl group of ketone takes place. For carbonyl protection, ethylene glycol is the commonly used group. The final product resembles like ether and known as ketal during the protection of carbonyl group using ethylene glycol. The product of this reaction is shown below.

i) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, aniline $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{NH}}_{\text{2}}\right)$.

The reaction of ketone with primary amine results in the formation of imine. The product of this reaction is shown below.

j) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, dimethylamine, p-toluenesulfonic acid, benzene.

The reaction of ketone with secondary amine forms enamine as the final product. The reaction of cyclopentanone with dimethylamine in the presence of p-toluenesulfonic acid and benzene gives $\text{cyclopent-2-enyl-dimethyl-amine}$ as the final product. The product of this reaction is shown below.

k) The product obtained by the reaction between the given compound, cyclopentanone and the reagent, hydroxylamine.

The reaction of cyclopentanone with hydroxylamine results in the formation of cyclopentanone oxime. The product of this reaction is shown below.

l) The product obtained by the reaction between cyclopentanone and the reagent, hydrazine.

The reaction of cyclopentanone with hydrazine gives cyclopentylidene hydrazine as the final product. The product of this reaction is shown below.

m) The product obtained by the reaction between cyclopentanone and the product of part (l) heated in triethylene glycol with sodium hydroxide.

The reaction of ketone with hydrazine gives hydrazone. The reaction of cyclopentanone with hydrazine gives cyclopentylidene hydrazine as the final product. The heating of cyclopentylidene hydrazine in triethylene glycol with sodium hydroxide forms cycloalkane as the final product. The product of this reaction is shown below.

n) The product obtained by the reaction between cyclopentanone and p-nitrophenylhydrazine.

The reaction of ketone with hydrazine gives hydrazone. The reaction of cyclopentanone with p-Nitrophenylhydrazine gives hydrazone as the final product. The product of this reaction is shown below.

o) The product obtained by the reaction between cyclopentanone and semicarbazide.

The reaction of ketone with semicarbazide results in the formation of semicarbazone. The reaction of propanal with ${\text{H}}_{\text{2}}{\text{NNHCONH}}_{\text{2}}$ forms ${\text{H}}_8{\text{C}}_5{\text{=N-NHCONH}}_{\text{2}}$. The final product of this reaction is shown below.

p) The product obtained by the reaction between cyclopentanone and ethylidenetriphenylphosphorane.

The reaction of cyclopentanone with ethylidenetriphenylphosphorane gives ethylidenecyclopentane as the final product. The product of this reaction is shown below.

q) The product obtained by the reaction between cyclopentanone and sodium cyanide with addition of sulfuric acid.

The reaction of ketone with sodium cyanide results in the formation of cyanohydrin. The product of this reaction is shown below.

r) The product obtained by the reaction between cyclopentanone and chromic acid.

The reaction of ketone with chromic acid results in the formation of carboxylic acids. The reaction of cyclopentanone with chromic acid gives pentanedioic acid as the final product. The product of this reaction is shown below.